Sero-prevalence and intrinsic factors associated with Brucella infection in food animals slaughtered at abattoirs in Abuja, Nigeria

Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

Brucellosis is considered one of the most hazardous zoonotic diseases all over the world. It causes formidable economic losses in developed and developing countries. Despite the significant attempts to get rid of Brucella pathogens in many parts of the world, the disease continues to spread widely. Recently, many attempts proved to be effective for the prevention and control of highly contagious bovine brucellosis, which could be followed by others to achieve a prosperous future without rampant Brucella pathogens. In this study, the updated view for worldwide Brucella distribution, possible predisposing factors for emerging Brucella pathogens, immune response and different types of Brucella vaccines, genomics and proteomics approaches incorporated recently in the field of brucellosis, and future perspectives for prevention and control of bovine brucellosis have been discussed comprehensively. So, the current study will be used as a guide for researchers in planning their future work, which will pave the way for a new world without these highly contagious pathogens that have been infecting and threatening the health of humans and terrestrial animals.

Human and Animal Brucellosis in Nigeria: A Systemic Review and Meta-Analysis in the Last Twenty-One Years (2001–2021)

Simple Summary

Brucellosis caused by Brucella spp. is transmitted by direct or indirect contact with infected animals or their secretions and through the consumption of infected animal meat and unpasteurized milk/milk products. Brucellosis is classified as one of the top neglected zoonosis by the World Health Organization (WHO), and despite this, it does not attract the appropriate attention it requires from both the Federal and State ministries of health in Nigeria. Currently, there is a lack of coordinated national data on the prevalence and distribution of human and animal brucellosis. Thus, published research works between 2001 and 2021 were studied based on set criteria to estimate the burden and distribution of brucellosis in Nigeria. The results of the national seroprevalence of human and animal brucellosis were 17.6% (554/3144) and 13.3% (8547/64,435), respectively. Specifically, 15.8% (7178/45,363) seroprevalence of brucellosis was recorded in northern Nigeria as against 8.7% (1902/21,740) in the southern part. Brucella abortus, B. melitensis, B. suis, and B. canis were reported in 27 of the 36 states. Improved sanitation at the abattoirs, use of personal protective equipment by animal handlers, vaccination of animals against brucellosis, and ranching of animals to curb the spread of the disease should be paramount to all stakeholders.

Abstract

The global burden of human and animal brucellosis remains enormous. The disease, which is endemic in Nigeria, lacks appropriate attention and national data. This review estimated the burden and distribution of human and animal brucellosis in Nigeria in the last twenty-one years (2001–2021). Publications reporting the detection of brucellosis in Nigeria were sorted from different search engines, including PubMed, ResearchGate, Scopus, and Google Scholar, to generate data on its prevalence, spatial distribution, and predisposing factors. The results of the national seroprevalence of human and animal brucellosis as revealed in this study were 17.6% (554/3144) and 13.3% (8547/64,435), respectively. Specifically, 15.8% (7178/45,363) seroprevalence of brucellosis was recorded in northern Nigeria as against 8.7% (1902/21,740) seroprevalence in the southern part. It also indicated that 78.7% of the detected brucellae were un-typed. The Brucella species detected were B. abortus (15.2%), B. melitensis (4%), B. suis (1.8%), and B. canis (0.4%). This study revealed that brucellosis is endemic in Nigeria. Culture and molecular methods for detecting brucellosis and reports on antimicrobial susceptibility testing remain a conjecture. This review will help researchers redirect their research focus and serve as a guide for policymakers on measures for managing brucellosis in Nigeria.

Strengthening the global one health workforce: Veterinarians in CDC-supported field epidemiology training programs

Background

Effective prevention, detection, and response to disease threats at the human-animal-environment interface rely on a multisectoral, One Health workforce. Since 2009, the U.S. Centers for Disease Control and Prevention (CDC) has supported Field Epidemiology Training Programs (FETPs) to train veterinarians and veterinary paraprofessionals (VPPs) alongside their human health counterparts in the principles of epidemiology, disease surveillance, and outbreak investigations. We aim to describe and evaluate characteristics of CDC-supported FETPs enrolling veterinarians/VPPs to understand these programs contribution to the strengthening of the global One Health workforce.

Methods

We surveyed staff from CDC-supported FETPs that enroll veterinarians and VPPs regarding cohort demographics, graduate retention, and veterinary and One Health relevant curriculum inclusion. Descriptive data was analyzed using R Version 3.5.1.

Results

Forty-seven FETPs reported veterinarian/VPP trainees, 68% responded to our questionnaire, and 64% reported veterinary/VPP graduates in 2017. The veterinary/VPP graduates in 2017 made up 12% of cohorts. Programs reported 74% of graduated veterinarians/VPPs retained employment within national ministries of agriculture. Common veterinary and One Health curriculum topics were specimen collection and submission (93%), zoonotic disease (90%) and biosafety practices (83%); least covered included animal/livestock production and health promotion (23%) and transboundary animal diseases (27%). Less than half (41%) of programs reported the curriculum being sufficient for veterinarians/VPPs to perform animal health specific job functions, despite most programs being linked to the ministry of agriculture (75%) and providing veterinary-specific mentorship (63%).

Conclusions

Our results indicate that FETPs provide valuable training opportunities for animal health sector professionals, strengthening the epidemiology capacity within the ministries retaining them. While veterinary/VPP trainees could benefit from the inclusion of animal-specific curricula needed to fulfill their job functions, at present, FETPs continue to serve as multisectoral, competency-based, in-service training important in strengthening the global One Health workforce by jointly training the animal and human health sectors.

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Global health security requires multisectoral epidemiology workforce capacity.

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FETPs with veterinarians/VPPs were linked to ministries of agriculture and health.

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Veterinary/VPP FETP trainees jointly train alongside public health epidemiologists.

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One Health and Zoonotic Diseases curriculum was offered by most FETPs.

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FETPs train in epidemiology and surveillance at human-animal-environment interface.

Seroprevalence of brucellosis and Q fever infections amongst pastoralists and their cattle herds in Sokoto State, Nigeria

Brucellosis and Q fever are neglected zoonoses of global health importance, with unknown true prevalence in occupationally vulnerable settings, partly due to misdiagnosis for other febrile conditions and poor access to primary health care. We examined the seroprevalence of these diseases and associated factors amongst pastoralists and their cattle in Sokoto State, a hub of cattle and pastoral populations in Nigeria. Serum samples randomly collected from 137 pastoralists and 366 cattle from 27 herds in three selected Local Government Areas (LGAs) in the state were analysed for antibodies to Brucella abortus using Rose Bengal Plate Test (RBT) and competitive Enzyme-Linked Immunosorbent Assay (cELISA) as well as antibodies to Coxiella burnetti using indirect ELISA. Consenting pastoralists' knowledge, perception and practices about the diseases were assessed using a semi-structured questionnaire. Data were analysed using descriptive statistics and bivariate analysis at p ≤ 0.05 level of significance. Brucellosis adjusted individual seroprevalence were 0.83% (95%CI: 0.04-4.59%) and 0% among pastoralists; 2.28% (95%CI: 1.16-4.43%) and 5.70% (95%CI: 3.68-8.74%) in cattle by RBT and cELISA, respectively. Adjusted herd-level seroprevalence for brucellosis were 23.20% (95%CI: 11.07-42.54%) and 42.00% (95%CI: 25.27-61.11%) by RBT and cELISA, respectively. For Q fever, higher seroprevalence of 62.57% (95%CI: 54.04-70.46%) and 2.98% (95%CI: 1.57-5.58%) were recorded amongst the pastoralists and their cattle, respectively. with adjusted herd-level seroprevalence of 40.36% (95%CI: 22.57-63.17%). The LGAs of sampling were significantly (OR: 0.2; 95%CI: 0.02-1.00) associated with Q fever infection, though marginal. The majority of the pastoralists had poor knowledge, perception and practices towards the diseases. This is the first study establishing the presence of brucellosis and Q fever at the human-animal interface in Sokoto State, Nigeria. The pastoralists' poor knowledge, perception and practices about these diseases are worrisome and are important factors for consideration in disease control.

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

Seroprevalence of brucellosis and Q fever (Coxiellosis) in cattle herds in Maigana and Birnin Gwari agro-ecological zone of Kaduna State, Nigeria

A cross sectional study was conducted to determine the seroprevalence and risk factors of brucellosis and Q fever in cattle in Maigana and Birnin Gwari agro-ecological zone of Kaduna State, Nigeria. This study aimed at determining the significance of Brucella spp. and Coxiella burnetti infections in cattle. A total of 400 sera samples (139 from males and 261 from females cattle) were collected and screened for brucellosis using Rose Bengal Plate test (RBPT) and competitive enzyme linked immunosorbent assay (cELISA) for brucellosis and indirect enzyme-linked immunosorbent assay (iELISA) for Q fever. A structured questionnaire was used to collect data on the sampled animals from the study population. Data were analyzed to determine association and risk factors. Sera analysis revealed that, 18.5 and 6.8% were seropositive by RBPT and cELISA for brucellosis, while 6.2% was seropositive by iELISA for Q fever. A significant association was detected between cattle sex and sensitivity of RBPT for detecting Brucella. Meanwhile, a non-significant association was found between cattle age and breed with sensitivity of RBPT, cELISA, and iELISA. The study indicates that brucellosis and Q ever exist with high prevalence particularly among female cattle. This presents a serious public health problem, calling for greater awareness among stakeholders and for co-ordinated surveillance for the diseases among cattle populations in Nigeria.